James p



(No Model.)

J. P. HANSON & J. P. CHRISTENSEN.

ELECTRIC BURGLAR ALARM.

Patented Feb 5, 1884-.

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.Waz-ZZ Z UNTTED STATES PATENT JAMES I. ILXXSOX AXD JAMES I. OHRISTEXSEX, OI? CHICAGO, llililX (115%.

ELECTRlC BURGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 292,807, dated February 5, 1884.

Application tiled May 10,1883. (No model..

To (tZZ whom it may concern:

Be it known that we, J .uIEs I. H .msoX and JAMES P. Gnnis'rnxsn citizens of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Electric Burglar-Alarms, of which the fol lowing is a specification, reference being had therein to the accompanying drawings.

This invention has for its object to produce a device that is connected with the shade or curtain of a window in a manner to set in motion an electric alarm-bell with the removal or pushing aside of such curtain; and it con sists of an apparatus secured to the windowi'raine, and having a vibratable bar provided with spring clamp-jaws, that grasp the edge of the curtain, and held on a central position by aspring-stem to form an incomplete cir cuit, by wire-connections with a galvanic battery and an alarm-bell, which circuit will be completed by the movement of the curtain in any direction that will release the clampbar from its central hold, and will bring it in contact with the internal surface of a surrounding metal rim, all as more fully hereinafter described, and specifically claimed.

In the drawings, Figure 1 represents a perspective view of the apparatus as attached to a window-frame, and Fig. 2 a longitudinal section of the same.

Corresponding letters in the several figures ot' the drawings designate like parts.

A denotes the base-plate, having two posts, a and a, that are tapped for concave-ended screws I), which hold between a small mandrel, 0, having conicallypointed ends that enter the concaved ends of such screws b. Upon the center of this mandrel c is pivotally secured the slotted middle portion of a bar, B, by a pin, (7, that is passed through holes in the center of such bar B and mandrel c in a manner that such bar B has a free universal vibrating movement between the screws 1) of posts a. The forward end of bar 13 has spring-jaws 0, between which the edge of a curtain is inserted to grasp and hold onto such curtain. The opposite end of bar B is concavcd, and holds a small rubber cup,

f. Upon plate A secured by a screw, on a column, h, the expanded rim i of a tube, I, that forms the guide for a stem, J, having a collar, j, and a head, K, and being pushed forward by a spiralspring, m. The pointed end of this stein J, when inserted into the concaved end of bar 13, will hold such bar on a central position, and out of contact with the interior surface of rim i. The screw 5 and column'h are insulated from plate A by interposing rubber washers o. A post, I is secured upon the forward end of plate A, and has a screw, p, for coupling one of the circuit-wires, r from which the electric current passes through plate A, posts (1, screws Z), and mandrel c, to bar I3. The other circuit-wire, r, is coupled to column 71, to lead the electric current to tube I. This circuit is incomplete as long as the point of stem J is engaged with the insulating-cup f of the concavcd end of bar B; but as soon as such bar 3, by a transverse foree, is released from stem J, such bar will vibrate, and will come in contact with the internal surface of rim 1', whereby the electric circuit is completed, and the alarm-bell will ring.

This apparatus, being secured to one side of a window-frame, with its spring-jaws grasp ing the edge of the curtain, a burglar, in trying to enter the house through the window, and raising or pushing to one side the cur tain, will turn the bar 13 away from its con tral hold, and will thus connect the electric circuit to ring the electric bell, that will reuse the inhabitants.

This device is simple in its construction, and reliable in its operation. and with a slight change it can as well be applied to inside blinds, or to announce the opening oi a window.

"hat we claim is 1. In an electric burglaralarm provided with suitable circuit-com]ections, the bar I}.

I universally pivoted between posts a a of plate A, and having insulating-cup f, in combination with tube I, insulated from plate A, and having expanded rim i and spring-stem J, all substantially as described, to operate as specified.

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2 wa e:

2. In an electric burglar-alarm provided In testimony whereof we affix our signature3 with suit-able circuit-connections, the bar B, 1 in presence of two witnesses. nniversall )ivoted between posts cm of plate T T A,having s pring-jaws a and insulating-cup 5 f, in combination with tube I, insulated from plate A, and having expanded rim 6 and Witnesses: spring-stem J, all substantially as and for the ADAM Gno. XVIHTE, purpose described, to operate as specified. I R. G. Scrum). 

